/Engine/Source/Runtime/Datasmith/CADKernel/Public/CADKernel/Geo/Surfaces/Surface.h
A surface is closed along an iso axis if it's connected to itself e.g. the edge carried by the iso curve U = UMin is linked to the edge carried by the iso curve U = UMax A complete sphere, torus are example of surface closed along U and V A cylinder with circle section or a cone are example of surface closed along an iso
virtual void IsSurfaceClosed ( bool & bOutClosedAlongU, bool & bOutClosedAlongV ) const